Why does the ringtone set by Xiaomi 4 mobile phone always change automatically?

1, the ringtone file set by the user is lost, damaged or changed, and the mobile phone system can't find the ringtone file, so it will automatically switch back to the system default ringtone; You can reset the ringtone, and it is best not to change the location or delete the ringtone file; Try to choose from the ringtones that come with the system.

2. If there is something wrong with the system, it will automatically change back to the default ringtone after setting. You can restart your phone and try setting again. If necessary, you can consider resetting the system or upgrading the system to solve it.